It’s the presidential seal of approval.

Former President Barack Obama’s newly revealed call with mayoral front-runner Zohran Mamdani is a nod that could help make the socialist more palatable to panicking high-level Democrats, insiders tell The Post.

Details about the June call — first reported by New York Times staff writer Mara Gay on Wednesday and confirmed by The Post — remain vague, but its disclosure appears to be part of an effort to persuade holdout Big Apple voters that Mamdani is not a fringe candidate.

“It gives the sense that President Obama’s world is comfortable with his candidacy. It normalizes him,” the Rev. Al Sharpton, who had close ties with Obama’s White House, said Thursday.

“It helps with the perception of some people that Mamdani is too radical. It sends a message that he is not unacceptable,” Sharpton said.

Mamdani, speaking in The Bronx during his “Five Boroughs Against Trump” tour Thursday, only gave broad strokes details about his call with Obama and sidestepped questions on an endorsement.

“I leave the decision of endorsements to the president,” he said.

“We spoke about the importance in a moment such as this, where politics is often characterized by a language of darkness, the necessity of hope, and how we speak and how we orient ourselves to the world.”

A source in Mamdani’s campaign said they hope Obama’s interest leads to an endorsement — which the progressive phenom has failed to secure from prominent mainstream Empire State Dems such as Gov. Kathy Hochul, US Senate Minority Leader Chuck Schumer and House Minority Leader Hakeem Jeffries.

“Zohran Mamdani is the future of the Democratic Party,” the source argued. “Zohran inspired people to get involved in the political party. President Obama recognized this.”

But regardless of whether the call portends a future endorsement, just news of it was a boon to the Mamdani camp, politicos said.

“It helped their candidate, even if Obama’s call was only to congratulate Mamdani after his primary win,” said Ken Frydman, a Democratic political operative.

Another Democratic source suggested it could also shore up Mamdani’s support among black voters, a bloc that has been largely ambivalent toward him. 

“Whether it’s true or not, that’s how all good propaganda works,” the source said. 

Former Gov. Andrew Cuomo – whose embarrassing defeat by Mamdani in the mayoral primary has imperiled his hopes of a political comeback – defensively argued to The Post that Obama’s call doesn’t show the socialist is being embraced by mainstream Democrats.

”Did he endorse him?” Cuomo asked of Obama. “Then I don’t know what ‘embraced’ means.”

Mamdani has racked up a slew of Democratic endorsements, including from fellow progressive firebrand Rep. Alexandria Ocasio-Cortez (D-Bronx), Rep. Nydia Velasquez (D-Brooklyn) and Rep. Jerrold Nadler (D-Manhattan), who appeared with him as he kicked off his anti-Trump five-borough tour this week. 

He also received endorsements from three of five Democratic Party county organizations in the city, with the Bronx and Queens being the holdouts.

State Assembly Speaker Carl Heastie is the Democrats’ big cheese in the Bronx and Rep. Gregory Meeks, a close ally of Jeffries, holds sway in Queens. Neither has endorsed Mamdani.

And the top state Dems Hochul, Jeffries and Schumer, as well as Sen. Kirsten Gillibrand, have pointedly held off endorsing Mamdani. 

Gillibrand ripped Mamdani for refusing to condemn the “globalize the intifada” rallying cry, but also apologized to him for falsely claiming he pushed for “global jihad.”

Schumer has largely kept silent on Mamdani, although he said he’ll powwow with him.

Jeffries said he would meet with Mamdani for a second time after the candidate returned from a trip to Uganda, but that hasn’t happened.

A source said Jeffries’ time has been dominated by the redistricting battle in Texas and Chicago and he’s not dodging Mamdani.

Hochul, during a Fox News interview Sunday, defended taking a wait-and-see approach with Mamdani.

“We still have many differences,” she said. “I don’t know how you whitewash that away.”

But Hochul did signal that she’d work with Mamdani if he wins the mayoralty.

“I will make it work out because I’m not going to go to war with the 8 million residents of New York that I also represent,” she said, before seemingly extending a tentative olive branch, “But people have to recognize what that candidate for mayor has also touched a nerve, and we need to be responsive to that.

“So, I’m aligned with him that we need to start finding ways to make life more affordable for New Yorkers.”

Mamdani has ties to Obama’s orbit through Patrick Gaspard, the ex-president’s former White House political director and ambassador to South Africa, who is an unpaid adviser to the Queens assemblyman.

Gaspard accompanied Mamdani the last four times Sharpton met with the Democratic socialist — twice at National Action Network events, once during a meeting with a group of NAN pastors and recently during a meal at the Regency hotel.

Sharpton said he didn’t not know if Obama would end up endorsing in the mayor’s race.

Other sources cautioned that Obama’s call may have been more of a courtesy, congratulating the Democratic mayoral nominee, rather than a genuine sign he’ll endorse Mamdani.

Four years ago, Obama, Schumer, Rep. Nancy Pelosi and other prominent Democrats all called then-Brooklyn Borough President Eric Adams after his mayoral primary win, a political source pointed out.

“That’s just maintenance for those guys,” the source said. “They want to stay relevant with the party and leadership.”

The source argued the fact that Bill and Hillary Clinton aren’t endorsing Mamdani and Obama isn’t confirming any support for him “tells you all you need to know.”

Adams, when asked about the call between Mamdani and Obama, dismissed what “national leaders are doing.”

“It’s about New York City residents,” he said.

Hizzoner ignored The Post’s question about whether he has talked to Obama since 2021.

— Additional reporting by Khristina Narizhnaya